Howto add properties to the output of unordered_list? - django

Question

I am using an unordered_list tag in django.
I have the following list:
foo = ['A', ['B', 'C', 'D'], 'E']
And the following tag:
{{ foo|unordered_list }}
Which produces, as expected the following:
<li>A
<ul>
<li>B</li>
<li>C</li>
<li>D</li>
</ul>
</li>
<li>E</li>
What I would like to do is to add id and class properties to each "li" node.
I understand that I can do it in JavaScript, or implement my own template tag in django. But I wanted to ask first. May be there already exists an easy build-in way to do it in django template?

Answer 1

As you can see in the source, the <li> is hardcoded so you can't do it without creating your own templatefilter.
def unordered_list(value, autoescape=None):
"""
Recursively takes a self-nested list and returns an HTML unordered list --
WITHOUT opening and closing <ul> tags.
The list is assumed to be in the proper format. For example, if ``var``
contains: ``['States', ['Kansas', ['Lawrence', 'Topeka'], 'Illinois']]``,
then ``{{ var|unordered_list }}`` would return::
<li>States
<ul>
<li>Kansas
<ul>
<li>Lawrence</li>
<li>Topeka</li>
</ul>
</li>
<li>Illinois</li>
</ul>
</li>
"""
if autoescape:
from django.utils.html import conditional_escape
escaper = conditional_escape
else:
escaper = lambda x: x
def convert_old_style_list(list_):
"""
Converts old style lists to the new easier to understand format.
The old list format looked like:
['Item 1', [['Item 1.1', []], ['Item 1.2', []]]
And it is converted to:
['Item 1', ['Item 1.1', 'Item 1.2]]
"""
if not isinstance(list_, (tuple, list)) or len(list_) != 2:
return list_, False
first_item, second_item = list_
if second_item == []:
return [first_item], True
old_style_list = True
new_second_item = []
for sublist in second_item:
item, old_style_list = convert_old_style_list(sublist)
if not old_style_list:
break
new_second_item.extend(item)
if old_style_list:
second_item = new_second_item
return [first_item, second_item], old_style_list
def _helper(list_, tabs=1):
indent = u'\t' * tabs
output = []
list_length = len(list_)
i = 0
while i < list_length:
title = list_[i]
sublist = ''
sublist_item = None
if isinstance(title, (list, tuple)):
sublist_item = title
title = ''
elif i < list_length - 1:
next_item = list_[i+1]
if next_item and isinstance(next_item, (list, tuple)):
# The next item is a sub-list.
sublist_item = next_item
# We've processed the next item now too.
i += 1
if sublist_item:
sublist = _helper(sublist_item, tabs+1)
sublist = '\n%s<ul>\n%s\n%s</ul>\n%s' % (indent, sublist,
indent, indent)
output.append('%s<li>%s%s</li>' % (indent,
escaper(force_unicode(title)), sublist))
i += 1
return '\n'.join(output)
value, converted = convert_old_style_list(value)
return mark_safe(_helper(value))
unordered_list.is_safe = True
unordered_list.needs_autoescape = True
It should be fairly easy to rewrite the filter to add id/class support though, depending on how you want it to work.